To help cut down on oil consumption and pollution, the International Maritime Organization, the United Nations agency that oversees maritime safety, this August will begin enacting a heavy-fuels ban, effectively restricting ships with more than 500 passengers from visiting Antarctica. According to some estimates, the change will reduce the number of annual visitors from 33,000 to 24,000. What this means for you: prices will eventually rise, but once you reach Antarctica you'll have a lot more elbow room. Which is nice, not only for the continent's environmental health but also for celebrating: 2011 is the 100th anniversary of Roald Amundsen's expedition to the South Pole. Polar Explorers is mounting a 700-mile ski expedition in honor of Amundsen ($65,000; November 12–January 12) as well as several shorter trips that will fly close to the pole and ski the last 12 miles ($52,500). Polarexplorers.com. Explorers Corner leads a ballsy monthlong sea-kayaking trip for expert paddlers. The trip, based off the 54-foot S/V Northanger expedition ship, leaves from Ushuaia, Argentina, and crosses the Drake Passage. Then it's two weeks of paddling (8 to 14 miles per day) and chilly camping. From $14,500; February 22–March 21, 2012; explorerscorner.com.